Processes for coating reticulated foams

ABSTRACT

A substrate for use in an aqueous slurry has a polymeric coating to provide a compliant and sticky surface. The polymer coating has a chemical to render the surface hydrophobic so as to attract hydrophobic or hydrophobized mineral particles in the slurry. The substrate can take the form of a conveyor belt, a bead, a mesh, an impeller, a filter or a flat surface. The substrate can also be an open-cell foam. The polymeric coating can be modified with tackifiers; plasticizers; crosslinking agents; chain transfer agents; chain extenders; adhesion promoters; aryl or alky copolymers; fluorinated copolymers and/or additives; hydrophobizing agents such as hexamethyldisilazane; inorganic particles such as silica, hydrophobic silica, and/or fumed hydrophobic silica; MQ resin; and/or other additives to control and modify the properties of the polymer.

CROSS-REFERENCE TO RELATED PATENT APPLICATIONS

The present application claims the benefit of U.S. Provisional PatentApplication No. 62/464,560, filed 28 Feb. 2017, entitled “Processes forcoating reticulated foams”, which is incorporated by reference herein inits entirety.

The present application is related to PCT application No.PCT/US17/59560, filed 02, Nov. 2017, entitled “Polymer coating forselective separation of hydrophobic particles in aqueous slurry”(712-002.441-1/CCS0177WO), which claims the benefit of U.S. ProvisionalPatent Application No. 62/416,314, filed 2 Nov. 2016, entitled “Polymercoating for selective separation of hydrophobic particles in aqueousslurry”, which are incorporated by reference herein in their entirety.

The present application is related to pending U.S. patent applicationSer. No. 15/401,755, filed 9 Jan. 2017(712-002.428-2), entitled“Recovery media for mineral processing, using open cell or reticulatedfoam having 3-dimensional functionalized open-network structure forselective separation of mineral particles in an aqueous system”, whichis a continuation-in-part application of PCT application PCT/US12/39534,filed 25 May 2012 (Docket No. 712-002.359-1/CCS-0087), entitled “Mineralseparation using functionalized membrane”, which claims the benefit ofU.S. provisional application No. 61/489,893, filed 25 May 2011 and U.S.provisional application No. 61/533,544, filed 12 Sep. 2011, which areall incorporated by reference herein in their entirety.

This application is also related to a family of eight PCT applications,which were all concurrently filed on 25 May 2012, as follows:

PCT application no. PCT/US12/39528 (Atty docket no. 712-002.356-1),entitled “Flotation separation using lightweight synthetic bubbles andbeads;”

PCT application no. PCT/US12/39540 (Atty docket no. 712-002.359-2),entitled “Mineral separation using sized, weighted and magnetizedbeads;”

PCT application no. PCT/US12/39576 (Atty docket no. 712-002.382),entitled “Synthetic bubbles/beads functionalized with molecules forattracting or attaching to mineral particles of interest,” whichcorresponds to U.S. Pat. No. 9,352,335;

PCT application no. PCT/US12/39591 (Atty docket no. 712-002.383),entitled “Method and system for releasing mineral from synthetic bubblesand beads;”

PCT application no. PCT/US/39596 (Atty docket no. 712-002.384), entitled“Synthetic bubbles and beads having hydrophobic surface;”

PCT application no. PCT/US/39631 (Atty docket no. 712-002.385), entitled“Mineral separation using functionalized filters and membranes,” whichcorresponds to U.S. Pat. No. 9,302,270;”

PCT application no. PCT/US12/39655 (Atty docket no. 712-002.386),entitled “Mineral recovery in tailings using functionalized polymers;”and

PCT application no. PCT/US12/39658 (Atty docket no. 712-002.387),entitled “Techniques for transporting synthetic beads or bubbles In aflotation cell or column,” all of which are incorporated by reference intheir entirety.

This application also related to PCT application no. PCT/US2013/042202(Atty docket no. 712-002.389-1/CCS-0086), filed 22 May 2013, entitled“Charged engineered polymer beads/bubbles functionalized with moleculesfor attracting and attaching to mineral particles of interest forflotation separation,” which claims the benefit of U.S. ProvisionalPatent Application No. 61/650,210, filed 22 May 2012, which isincorporated by reference herein in its entirety.

This application is also related to PCT/US2014/37823, filed 13 May 2014,entitled “Polymer surfaces having a siloxane functional group,” whichclaims benefit to U.S. Provisional Patent Application No. 61/822,679(Atty docket no. 712-002.395/CCS-0123), filed 13 May 2013, which isincorporated by reference herein in its entirety.

This application also related to PCT application no. PCT/US13/28303(Atty docket no. 712-002.377-1/CCS-0081/82), filed 28 Feb. 2013,entitled “Method and system for flotation separation in a magneticallycontrollable and steerable foam,” which is also hereby incorporated byreference in its entirety.

This application also related to PCT application no. PCT/US16/57334(Atty docket no. 712-002.424-1/CCS-0151), filed 17 Oct. 2016, entitled“Opportunities for recovery augmentation process as applied tomolybdenum production,” which is also hereby incorporated by referencein its entirety.

This application also related to PCT application no. PCT/US16/37322(Atty docket no. 712-002.425-1/CCS-0152), filed 17 Oct. 2016, entitled“Mineral beneficiation utilizing engineered materials for mineralseparation and coarse particle recovery,” which is also herebyincorporated by reference in its entirety.

BACKGROUND OF THE INVENTION 1. Technical Field

This invention relates generally to a method and apparatus forseparating valuable material from unwanted material in an aqueousmixture, such as a pulp slurry.

2. Description of Related Art

In many industrial processes, flotation is used to separate valuable ordesired material from unwanted material. By way of example, in thisprocess a mixture of water, valuable material, unwanted material,chemicals and air is placed into a flotation cell. The chemicals areused to make the desired material hydrophobic, as well as to aid theformation of bubbles and the stability of the froth, and the air is usedto carry the material to the surface of the flotation cell. When thehydrophobic material and the air bubbles collide they become attached toeach other. The bubble rises to the surface carrying the desiredmaterial with it.

The performance of the flotation cell is dependent on the bubble surfacearea flux in the collection zone of the cell. The bubble surface areaflux is dependent on the size of the bubbles and the air injection rate.Controlling the bubble surface area flux has traditionally been verydifficult. This is a multivariable control problem and there are nodependable real time feedback mechanisms to use for control.

There is a need in the industry to provide a better way to separatevaluable material from unwanted material, e.g., including in such aflotation cell, so as to eliminate problems associated with using airbubbles in such a separation process.

SUMMARY OF THE INVENTION

The present invention provides a substrate for use in an aqueous slurry.The substrate has a polymeric coating to provide a compliant and tackysurface of low energy in order to enhance selective collection ofhydrophobic and hydrophobized mineral particles ranging widely inparticle size when distributed in an aqueous slurry. The substrate mayhave an open-cell foam structure. The polymer coating may be applied tothe open-cell foam structure, for example. The coating is arranged to behomogeneously distributed throughout the entire foam surface area whilenot blocking or plugging cells, thereby maximizing surface area andadhesion while minimizing coating agglomerates that may becomedisadvantageously detached in-use.

The polymeric coating also has a chemical to render the surfacehydrophobic so as to attract hydrophobic or hydrophobized mineralparticles in the slurry.

The coating may be comprised of a polysiloxane derivative; acrylicpolymer; butyl rubber; ethylene vinyl acetate; natural rubber; nitriles;styrene block copolymers with ethylene, propylene, and/or isoprene;polyurethane, and/or polyvinyl ethers. Systems of providing the thin,homogeneous coating throughout an open-cell foam with thickness between1/32″ and 6″ and pore size from 5 PPI to 120 PPI (pores per inch)include various embodiments. Each system may be followed with a heater,in certain cases containing added moisture and/or blowers, to acceleratecoating cure. In each case where an excess of coating is applied; thegap distance, along with the coating viscosity, coating and foam surfaceenergy, and foam density largely determines the coat weight andthickness. A doctor blade may also be used in these cases in order tometer the coating application. The various embodiments are as follows:

1) Two-roll flooded-nip coater. The two rollers are providedside-by-side horizontally with a thin gap between them. The roller speedand size is independently controlled and may be different for eachroller. The roller temperatures are individually controlled. The coatingis placed in excess into the roller gap and then the foam is fed intothat gap and through the roller system. The gap distance may be as lowas 2% of the foam thickness.

2) Spray manifold and roll coater. The coating is sprayed onto each sideof the foam in an amount equal to the desired coat weight or higher. Thecoated foam is then fed between two rollers to distribute the coatinghomogeneously throughout the foam structure. High viscosity coatings canbe diluted to reduce viscosity and make them sprayable. Temperature canbe increased to reduce viscosity; however, this should be balanced withthe pot life of curable coatings.

3) Extruder and roll coater. The coating is extruded onto one or bothsurfaces of the foam. The coated foam is then fed between two rollers todistribute the coating homogeneously throughout the foam structure.

4) Porous roll coater. The coating is fed through porous rolls thatcompress and apply the coating. The porous rolls may be made of metal orceramic or may be open-celled foams.

5) Immersion coater. The foam is fed through a bulk coating vesselfollowed by a roller system to eliminate excess coating.

6) Vacuum impregnation. The foam is placed in a bulk coating vessel withvacuum which draws the coating into the foam. The coated foam is thenfed between two rollers to distribute the coating homogeneouslythroughout the foam structure.

7) Metering-roll coaters. Various roll configurations may be used toapply the coating. A pick-up roll may be immersed in the coatingmaterial which is then offset onto the coating roll and onto the foam.The coating on a coating roll may be optimized by offsetting onto ametering roll, doctor roll, or doctor blade. A series of rolls can carrythe coating from a reservoir to a pick-up roll, transfer roll, thecoating roll and onto the foam. Excess coating can be removed by runningthe coated foam through a back-up roll and a Mayer bar or Wiper bar withthe excess dropping back into the reservoir.

Thus, the first aspect of the present invention is a process for coatinga substrate comprising a reticulated foam, the process comprising:

arranging a first roller and a second roller adjacent to each othersubstantially in a horizontal direction, the second roller and the firstroller separated by a gap, the gap having an upper portion and a lowerportion;

positioning the substrate on the upper portion of the gap, the substratehaving a substrate thickness greater than the gap;

providing a coating material onto the substrate, and

feeding the substrate from the upper portion of the gap through thelower portion of the gap so as to achieve a homogeneous coating of thecoating material on the substrate.

According to an embodiment of the present invention, the substrate hastwo surfaces arranged to contact both the first roller and the secondroller simultaneously through the gap.

According to an embodiment of the present invention, the coatingmaterial is provided on the upper portion of the gap, and the twosurfaces of the substrate are caused to pick up the coating materialwhile the substrate is moved through the upper portion of the gap towardthe lower portion of the gap.

According to an embodiment of the present invention, the coatingmaterial is sprayed onto the two surfaces of the substrate above thegap.

According to an embodiment of the present invention, the coatingmaterial is extruded onto one or both surfaces of the substrate abovegap.

According to an embodiment of the present invention, the first rollerand the second roller are porous rollers, and wherein the coatingmaterial is arranged to load onto the porous rollers so as to cause thecoating material on the porous rollers to transfer onto the substrate aspart of each rollers is compressed when the substrate is fed from theupper portion through the lower portion of the gap.

According to an embodiment of the present invention, the coatingmaterial is contained in a vessel, and the substrate is arranged to movethrough the vessel to pick up the coating material before the substrateis fed from the upper portion through the lower portion of the gap.

According to an embodiment of the present invention, the coatingmaterial is contained in a vacuum chamber and the substrate is arrangedto locate in the vacuum chamber in order to draw the coating materialonto the substrate before the substrate is fed from the upper portionthrough the lower portion of the gap.

According to an embodiment of the present invention, the process furthercomprises one or more rolls arranged to pick up the coating material andto transfer the picked up coating material onto the first roller and thesecond roller, and wherein the first and second rollers arranged toprovide the transferred coating material onto the substrate before thesubstrate is fed from the upper portion through the lower portion of thegap.

According to an embodiment of the present invention, the coatingmaterial is selected from the group consisting of a polysiloxanederivative, acrylic polymer, butyl rubber, ethylene vinyl acetate,natural rubber, nitriles, styrene block copolymers with ethylene,styrene block copolymers with propylene, styrene block copolymers withisoprene, polyurethane and polyvinyl ether.

According to an embodiment of the present invention, the reticulatedfoam comprises a plurality of pores having a pore size ranging from 5PPI to 120PPI.

According to an embodiment of the present invention, the reticulatedfoam has a foam thickness ranged from 1/32″ to 6″.

According to an embodiment of the present invention, the process furthercomprises a heater and/or a blower arranged to accelerate curing of thehomogeneous coating of the coating material on the substrate.

According to an embodiment of the present invention, the gap has a gapdistance ranged from 0.02 to 0.5 of the thickness of the substrate.

According to an embodiment of the present invention, the gap has a gapdistance which is 0.02 of the substrate thickness.

According to an embodiment of the present invention, the homogenouscoating is further functionalized to be hydrophobic so as to attractmineral particles in a slurry.

The second aspect of the present invent ion is a polymer-coated memberconfigured to contact a slurry containing mineral particles, thepolymer-coated member comprising:

a substrate comprising a reticulated foam having open-cell foamstructure, the substrate having two surfaces, the reticulated foamhaving a foam thickness;

a polymeric coating disposed on one or both of the two surfaces, thepolymeric-coating made from a coating material comprising a polymer torender the polymeric coating compliant and tacky, wherein the substrateis arranged to move through a pair of rollers arranged adjacent to eachother substantially in a horizontal direction, the rollers separatedfrom each other by a gap having an upper portion and a lower portion,wherein the coating material is arranged to provide onto the substrateabove the gap and the gap is dimensioned to compress the reticulatedfoam so as to impregnate the open-cell foam structure with the coatingmaterial when the substrate is moved from the upper portion of the gapthrough the lower portion of the gap to achieve the polymeric coating.

According to an embodiment of the present invention, the polymer coatingcomprises a chemical having a functional group rendering said one or twosurfaces hydrophobic so as to attract the miner particles.

According to an embodiment of the present invention, the polymericcoating is modified with a material selected from the group consistingof tackifiers; plasticizers; crosslinking agents; chain transfer agents;chain extenders; adhesion promoters; aryl or alky copolymers;fluorinated copolymers and/or additives; hydrophobizing agents such ashexamethyldisilazane; inorganic particles such as silica, hydrophobicsilica, and/or fumed hydrophobic silica; MQ resin; and/or otheradditives to control and modify the properties of the polymer.

According to an embodiment of the present invention, the polymericcoating is further modified with a chemical selected from the groupconsisting of with alkyl, aryl, and/or fluorinated functionalities;silica-based additives and other inorganics such as clays and/orbentonite; low molecular weight and oligomeric plasticizers; degrees ofcrosslinking density and branchedness (polymer structure); and/or POSSmaterials.

According to an embodiment of the present invention, the polymericcoating has a thickness ranged from 0.3 mils to 1.0 mils.

According to an embodiment of the present invention, the compliant andtacky surface has a tacky scale as measured by loop track againstpolished stainless steel using PSTC-16 Method A with loop tack in arange of 5 to 600 grams-force.

According to an embodiment of the present invention, the polymericcoating is reacted with additional functionality including oxyhydryl,sulfhydryl, or cationic functionality found in mineral collectors.

According to an embodiment of the present invention, the substrate maytake the form of a flat surface, a belt, a bead, a mesh, a filter, or animpeller. Each of the belt, bead, mesh, filter and impeller may have asurface or the entire body made of an open-cell foam.

According to an embodiment of the present invention, the substrate canbe an open-cell foam made from reticulated polyurethane.

According to an embodiment of the present invention, the substratecomprises an open-cell foam made from a material selected from the groupconsisting of silicone, polychloroprene, polyisocyanurate, polystyrene,polyolefin, polyvinylchloride, epoxy, latex, fluoropolymer, phenolic,EPDM, and nitrile.

According to an embodiment of the present invention, the substratecomprises a three-dimensional open cellular structure made of hardplastic.

According to an embodiment of the present invention, the mineralscomprise sulfide-based materials such as copper, gold, lead, zinc,nickel and iron.

According to an embodiment of the present invention, the minerals arefurther hydrophobized by addition of collector chemicals to the aqueousslurry, such as xanthate, dithiophosphate, dithiophosphinate,dithiocarbamate, thionocarbamate, hydroxamates, amine ethers, primaryamines, fatty acids and their salts.

The present invention will become apparent upon reading the descriptionin conjunction with FIGS. 1a to 14.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 includes FIG. 1a and FIG. 1b , where FIG. 1a is a side partialcutaway view in diagram form of a separation processor configured withtwo chambers, tanks or columns having a functionalized polymer coatedimpeller arranged therein according to some embodiments of the presentinvention, and FIG. 1b is a top partial cross-sectional view in diagramform of a functionalized polymer coated impeller moving in an attachmentrich environment contained in an attachment chamber, tank or column andalso moving in a release rich environment contained in a releasechamber, tank or column according to some embodiments of the presentinvention.

FIG. 2 is diagram of a separation processor configured with twochambers, tanks or columns having a functionalized polymer coatedconveyor belt arranged therein according to some embodiments of thepresent invention.

FIG. 3 is diagram of a separation processor configured with afunctionalized polymer coated filter assembly for moving between twochambers, tanks or columns in a semi-continuous batch process accordingto some embodiments of the present invention.

FIG. 4a shows a part of a generalized substrate, e.g., a member to becoated with the polymer, according to an embodiment of the presentinvention.

FIG. 4b shows a part of another member to be coated with the polymer,according to another embodiment of the present invention.

FIG. 4c illustrates a part of the member to be coated, according to adifferent embodiment of the present invention.

FIG. 4d illustrates a part of the member to be coated, according to yetanother embodiment of the present invention.

FIG. 4e illustrates a polymeric-coated substrate having a member asshown in FIG. 4 b.

FIG. 4f illustrates a polymeric-coated substrate having a member asshown in FIG. 4 d.

FIG. 5 illustrates a plurality of filters placed in a horizontalpipeline to collect mineral particles, according to some embodiments ofthe present invention.

FIG. 6 illustrates a release apparatus configured to release mineralparticles from a filter, according to some embodiments of the presentinvention.

FIG. 7 illustrates a filter placed in a tailings pond to collectvaluable material according to some embodiments of the presentinvention.

FIG. 8 illustrates a two-roll flooded-nip coater, according anembodiment of the present invention.

FIG. 9 illustrates a spray manifold and roll coater, according anembodiment of the present invention.

FIG. 10 illustrates an extruder and roll coater, according an embodimentof the present invention.

FIG. 11 illustrates a porous coater, according an embodiment of thepresent invention.

FIG. 12 illustrates an immersion coater, according an embodiment of thepresent invention.

FIG. 13 illustrates a coater with a vacuum impregnation vessel,according an embodiment of the present invention.

FIG. 14 illustrates a meter-roll coater, according an embodiment of thepresent invention.

DETAILED DESCRIPTION OF THE INVENTION

The present invention provides an apparatus for use in an aqueous slurrycontaining minerals and unwanted materials. The minerals includehydrophobic or hydrophobized mineral particles. The apparatus comprisesa substrate arranged to contact with the aqueous slurry and a polymericcoating disposed on the substrate. The polymeric coating has a compliantand tacky surface. The polymeric coating further comprises a chemical torender the surface hydrophobic so as to attract the hydrophobic orhydrophobized mineral particles.

According to an embodiment of the present invention, the polymericcoating provides a compliant, tacky surface of low energy to enhanceselective collection of hydrophobic and hydrophobized particles rangingwidely in particle size when distributed in an aqueous slurry. Forexample, the polymeric coating may be mounted on a substrate, such as aflat surface, belt, bead, mesh, filter, open cell foam structure, orother substrate.

By way of further example, open cell foam structures are disclosed incommonly owned U.S. Provisional Application Nos. 62/276,051, filed Jan.7, 2016 and 62/405,569, filed Oct. 5, 2016, which are all also herebyincorporated by reference in their entirety.

By way of still further example, PDMS coating and other media coatingmaterials are disclosed in commonly owned PCT application no.PCT/US2015/33485, filed 01 Jun. 2015, U.S. Pat. Nos. 9,352,335 and9,731,221, which are all hereby incorporated by reference in theirentirety.

As disclosed in the above references, the substrate coated with thepolymeric coating may be disposed within the aqueous slurry forinteraction with, and selective collection of, hydrophobic andhydrophobized particles. The aqueous slurry contains the hydrophobicand/or hydrophobized particles and may also contain unwanted particlesthat are less hydrophobic or are hydrophilic. For example, in the miningindustry, aqueous mining slurries contain a mixture of minerals andother materials The other materials in the slurry are typically referredto as “gangue materials,” and include various natural elements found ina mining deposit, such as sands, clays and other materials. Typically,the minerals and gangue material are ground to an average particle size.For example, depending on the mineral type, the average particle size ofthe mixture of minerals and gangue materials may range from fines ofonly several microns to coarse particles of greater than 800 microns.The ground minerals and gangue may be mixed with water to create theaqueous slurry. The minerals may be sulfide based minerals, such ascopper, gold, lead, zinc, nickel, iron or other mineral. However, otherminerals may be collected with the system of the present invention.Additionally, the minerals may be further hydrophobized by the additionof collector chemicals to the aqueous slurry, such as xanthate,dithiophosphate, dithiophosphinate, dithiocarbamate, thionocarbamate,hydroxamates, amine ethers, primary amines, fatty acids and their salts,and petroleum based collector chemistries commonly known in the miningindustry. Additionally, where there is a mixture of hydrophobic andhydrophobized particles to be collected, together with other materials,such as gangue, within the slurry, depressants may be added to theaqueous slurry to reduce the hydrophobicity of the gangue materials orother materials that are not desired to be collected by the polymericcoating. Examples of common depressants include cyanide, zinc sulfate,sulfur dioxide, sodium hydrosulfide, sodium sulfide, Nokes reagent,phosphates, diethylenetriamine, triethylenetetramine, certainamphiphilic polymers often based on polyacrylamide, and natural productssuch as starch, dextrin, CMC, tannin, quebracho, and lignosulfonates.

The polymer of the polymeric coating may be comprised of a polysiloxanederivative, such as, but not limited to, polydimethylsiloxane. Thepolymer may be modified with: tackifiers; plasticizers; crosslinkingagents; chain transfer agents; chain extenders; adhesion promoters; arylor alky copolymers; fluorinated copolymers and/or additives;hydrophobizing agents such as hexamethyldisilazane; inorganic particlessuch as silica, hydrophobic silica, and/or fumed hydrophobic silica; MQresin; and/or other additives to control and modify the properties ofthe polymer.

In another embodiment of the present invention, the coating may becomprised of other materials typically known as pressure sensitiveadhesives, including, but not limited to: acrylics; butyl rubber;ethylene vinyl acetate; natural rubber; nitriles; styrene blockcopolymers with ethylene, propylene, and/or isoprene; polyurethanes; andpolyvinyl ethers.

The materials listed above are formulated to be compliant and tacky withlow surface energy. All of these polymers may be mono-, bi-, ormulti-modal, and such materials may be modified with alkyl, aryl, and/orfluorinated functionalities; silica-based additives and other inorganicssuch as clays and/or bentonite; low molecular weight and oligomericplasticizers; degrees of crosslinking density and branchedness (polymerstructure); and/or POSS materials.

The modification in each case is to lower the surface energy and/oroptimize compliance and tack. Very effective coatings were prepared fromvarious modified silicones, acrylics, and ethylene vinyl acetate;however, all of the aforementioned polymers are effective if properlyprepared to include the desired qualities of lower surface energy,compliance and tack.

The compliance of the coating is a factor in determining the collectionefficiency of the hydrophobic particles on the coating as well as thedistribution of particle sizes collected on the coating. A fullynon-compliant hardened coating will not collect or only have verylimited collection of fines (small micron size particles) whereas anextremely soft coating, while collecting a large range of particles,lacks the cohesion to durably remain on its substrate in repeated use. Amoderately compliant coating allows particle adhesion while alsopossessing the cohesion necessary to remain on the substrate. Thecohesion of the coating is directly related to the durability of thecoating—the greater the cohesion of a particular coating, the greaterthe durability of that coating. Compliance is also affected by coatingthickness; therefore, coating thickness is also an important parameterin hydrophobic particle collection efficiency. It is known that uponcontact with a compliant surface, the compliance or “give” of thesurface may allow greater surface to surface contact between thecompliant surface and the object that comes in contact with thecompliant surface. In contrast, a non-compliant, or hard, surface wouldnot provide as much compliance, or give, when in contact with anotherobject, providing less potential surface contact. The coating of thepresent invention is designed to include a compliant surface thatprovides increased surface area contact between the coating and aparticle that comes in contact with the compliant coating; therebyenhancing adhesion forces. Coating thickness may be as low as 0.3 milsand greater than 1.0 mils, but is preferably greater than 0.75 mils (1mils=25.4 microns). In general, coatings with low compliancepreferentially collect smaller particle sizes while coatings with highercompliance collect a larger distribution of particle sizes.

Hydrophobic, compliant coatings have been prepared with minimal tackthat exhibit particle collection; however, enhanced collection isgenerally achieved when the coating is tacky as measured by loop tackagainst polished stainless steel using PSTC-16 Method A. Loop tack ispreferably greater than 5 grams-force, more preferably greater than 50grams-force, and most preferably greater than 100 grams-force. Veryeffective coatings were prepared with loop tack of 300-600 grams-force.

The polymeric coating may be reacted with additional functionalityallowing it to bond directly with a particle of interest. Thisfunctionality could include oxyhydryl, sulfhydryl, or cationicfunctionality found in mineral collectors.

The aforementioned coatings may be applied to any substrate effective inslurry processing. Substrates that may be coated include solid, hollow,or network structures made of glass, metal, ceramic, or polymer that maybe smooth or have rough surface morphology to improve coating adhesionand/or to increase surface area. The substrate may be comprised ofopen-cell foam comprised of reticulated polyurethane or anotherappropriate open-cell foam material such as silicone, polychloroprene,polyisocyanurate, polystyrene, polyolefin, polyvinylchloride, epoxy,latex, fluoropolymer, phenolic, EPDM, nitrile, composite foams and such.The substrate may be comprised of other three-dimensional open cellularstructures such as hard plastics, ceramics, carbon fiber, and metals maybe used. Examples include Incofoam®, Duocel®, metal and ceramic foamsproduced by American Elements®, and porous hard plastics such aspolypropylene honeycombs and such. The three-dimensional, open cellularstructure may itself form a compliant, tacky surface of low energy by,for example, forming such a structure directly from the coating polymersas described above.

The coated substrate must contact the aqueous slurry, be removed fromthe slurry, and then the hydrophobic particles removed from the coatedsubstrate to recover the valuable particles. This contact could occurwithin a flotation cell, an agitated tank, a tumbler or some other suchknown method of contact. The particle-rich coated substrate is thenremoved from the contactor and washed and/or blown to remove unwanted,unadhered gangue materials. Once any gangue material is removed, thehydrophobic particle laden substrate may be further processed to collectthe attached materials, such as attached minerals, for furtherprocessing.

Hydrophobic mineral particles of interest may include but not be limitedto hydrophobic and/or hydrophobicized metallic or nonmetallic mineralparticles, coal particles, diamond particles, or any hydrophobicparticles of value.

The three-dimensional open-cell structure may include pores ranging from5-200 pores per inch.

The substrate may include, or take the form of, a reticulated foam blockproviding the three-dimensional open-cell structure.

The substrate may include a filter providing the three-dimensionalopen-cell structure, the structure having open cells to allow fluid inthe aqueous mixture to flow through the filter.

The substrate may include a conveyor belt having a surface configuredwith the three-dimensional open-cell structure.

The substrate may include different open cell foams having differentspecific surface areas that are blended to recover a specific sizedistribution of mineral particles in the slurry.

Open Cell Foam and its Characteristics

The three-dimensional open-cell structure may take the form of open cellfoam. The open cell foam may be made from a material or materialsselected from a group that includes polyester urethanes, polyetherurethanes, reinforced urethanes, composites like PVC coated PU,non-urethanes, as well as metal, ceramic, and carbon fiber foams andhard, porous plastics, in order to enhance mechanical durability.

The open cell foam may be coated with polyvinylchloride, and then coatedwith a compliant, tacky polymer of low surface energy in order toenhance chemical and mechanical durability.

The open cell foam may be primed with a high energy primer prior toapplication of a functionalized polymer coating to increase the adhesionof the functionalized polymer coating to the surface of the open cellfoam.

The surface of the open cell foam may be chemically or mechanicallyabraded to provide “grip points” on the surface for retention of thefunctionalized polymer coating.

The surface of the open cell foam may be treated with a coating thatcovalently bonds to the surface to enhance the adhesion between thefunctionalized polymer coating and the surface.

The surface of the open cell foam may be coated with a functionalizedpolymer coating in the form of a compliant, tacky polymer of low surfaceenergy and a thickness selected for capturing certain mineral particlesand collecting certain particle sizes, including where thin coatings areselected for collecting proportionally smaller particle size fractionsand thick coatings are selected for collecting additional large particlesize fractions.

The specific surface area may be configured with a specific number ofpores per inch that is determined to target a specific size range ofmineral particles in the slurry.

Embodiment of Mineral Separation Apparatus

In its broadest sense, the present invention may take the form of amachine, system or apparatus featuring a first processor and a secondprocessor. The first processor may be configured to receive a mixture offluid, valuable material and unwanted material and a functionalizedpolymer coated member configured to attach to the valuable material inan attachment rich environment, and provide an enriched functionalizedpolymer coated member having the valuable material attached thereto. Thesecond processor may be configured to receive a fluid and the enrichedfunctionalized polymer coated member in a release rich environment torelease the valuable material, and provide the valuable materialreleased from the enriched functionalized polymer coated member to therelease rich environment.

The apparatus may be configured to include one or more of the followingfeatures:

The first processor may take the form of a first chamber, tank, cell orcolumn, and the second processor may take the form of a second chamber,tank, cell or column.

The first chamber, tank or column may be configured to receive a pulpslurry having water, the valuable material and the unwanted material inthe attachment rich environment, which has a high pH, conducive toattachment of the valuable material.

The second chamber, tank or column may be configured to receive water inthe release rich environment, which may have a low pH or receiveultrasonic waves conducive to release of the valuable material.

Although the invention is described as having a high pH in an attachmentenvironment and a low pH in a release environment, the present inventionwill work equally as well where the pH of the attachment environment isselected to optimize the attachment of desired materials, such as a low,high or neutral pH, and the pH of the release environment is selected tobe a different pH than the attachment environment and selected tooptimize the release of the desired material.

The functionalized polymer coated member may take the form of afunctionalized polymer coated impeller having at least one impellerblade configured to rotate slowly inside the first processor and thesecond processor. The first processor may be configured to receive theat least one impeller blade in an attachment zone, and provide at leastone enriched impeller blade having the valuable material attachedthereto in the attachment zone. The second processor may be configuredto receive the at least one enriched impeller blade in a release zoneand to provide the valuable material released from the at least oneenriched impeller blade. The first processor may be configured with afirst transition zone to provide drainage of tailings, and the secondprocessor may be configured with a second transition zone to providedrainage of concentrate.

As used herein with respect to functionalized polymer, the term“enriched” is intended to refer to a functionalized material that hasbeen exposed to a material of interest, and wherein the material ofinterest has been attached, attracted, connected or otherwise collectedby the functionalized material prior to release.

The functionalized polymer coated member may take the form of afunctionalized polymer coated conveyor belt configured to run betweenthe first processor and the second processor. The first processor may beconfigured to receive the functionalized polymer coated conveyor beltand provide an enriched functionalized polymer coated conveyor belthaving the valuable material attached thereto. The second processor maybe configured to receive the enriched functionalized polymer coatedconveyor belt and provide the valuable material released from theenriched functionalized polymer coated conveyor belt. The functionalizedpolymer coated conveyor belt may be made of a mesh material.

The functionalized polymer coated member may take the form of afunctionalized polymer coated collection filter configured to movebetween the first processor and the second processor as part of a batchtype process. The first processor may be configured to receive thefunctionalized polymer coated collection filter and to provide anenriched functionalized polymer coated collection filter having thevaluable material attached thereto. The second processor device may beconfigured to receive the enriched functionalized polymer coatedcollection filter and provide the valuable material released from theenriched functionalized polymer coated collection filter.

The first processor may be configured to provide tailings containing theunwanted material, and the second processor may be configured to providea concentrate containing the valuable material.

The functionalized polymer coated member may take the form of a membraneor a thin soft pliable sheet or layer.

According to some embodiment, the present invention may also take theform of apparatus featuring first means that may be configured toreceive a mixture of fluid, valuable material and unwanted material anda functionalized polymer coated member configured to attach to thevaluable material in an attachment rich environment, and provide anenriched functionalized polymer coated member having the valuablematerial attached thereto; and second means that may be configured toreceive a fluid and the enriched functionalized polymer coated member ina release rich environment to release the valuable material, and providethe valuable material released from the enriched functionalized polymercoated member to the release rich environment.

According to some embodiments of the present invention, the first meansmay be configured to receive a pulp slurry having water, the valuablematerial and the unwanted material in the attachment rich environment,which has a high pH, conducive to attachment of the valuable material;and the second means may be configured to receive water in the releaserich environment, which has a low pH or receives ultrasonic wavesconducive to release of the valuable material.

According to some embodiments of the present invention, thefunctionalized polymer coated member may take the form of one of thefollowing:

a functionalized polymer coated impeller having at least one impellerblade configured to rotate slowly inside the first means and the secondmeans;

a functionalized polymer coated conveyor belt configured to run betweenthe first means and the second means; or

a functionalized polymer coated collection filter configured to movebetween the first means and the second means as part of a batch typeprocess.

Embodiments of Mineral Separation Processes or Methods

According to some embodiment, the present invention may also take theform of a process or method featuring receiving in a first processor amixture of fluid, valuable material and unwanted material and afunctionalized polymer coated member configured to attach to thevaluable material in an attachment rich environment, and providing fromthe first processor an enriched functionalized polymer coated memberhaving the valuable material attached thereto; and receiving in a secondprocessor a fluid and the enriched functionalized polymer coated memberin a release rich environment to release the valuable material, andproviding the valuable material released from the enrichedfunctionalized polymer coated member to the release rich environment.

According to some embodiments of the present invention, the method mayinclude being implemented consistent with one or more of the featuresset forth herein.

The Synthetic Functionalized Polymer Coated Member Chemistry

According to some embodiments of the present invention, thefunctionalized polymer coated member may take the form of a substratecomprising a surface in combination with a plurality of moleculesattached to the surface, the molecules comprising a functional groupselected for attracting or attaching to one or more mineral particles ofinterest to the molecules. The term “polymer” in this specification isunderstood to mean a large molecule made of many units of the same orsimilar structure linked together.

According to some embodiments of the present invention, the substratemay be made of a synthetic material comprising the molecules. By way ofexample, the synthetic material may be selected from a group consistingof, but not limited to, polyamides (nylon), polyesters, polyurethanes,phenol-formaldehyde, urea-formaldehyde, melamine-formaldehyde,polyacetal, polyethylene, polyisobutylene, polyacrylonitrile, poly(vinylchloride), polystyrene, poly(methyl methacrylates), poly(vinyl acetate),poly(vinylidene chloride), polyisoprene, polybutadiene, polyacrylates,poly(carbonate), phenolic resin and polydimethylsiloxane.

According to some embodiments of the present invention, the functionalgroup may have an ionic group, which may be either anionic or cationic,for attracting or attaching the mineral particles to the surface.

According to some embodiments of the present invention, the functionalgroup may take the form of a collector having a non-ionizing bond havinga neutral or ionic functional group, or having an ionizing bond.

According to some embodiments of the present invention, the ionizingbond may be an anionic bond or a cationic bond. The anionic functionalgroup may be comprised of an oxyhydryl, including carboxylic, sulfatesand sulfonates, and sulfhydral bond.

Hydrophobicity

According to some embodiments of the present invention, the surface ofthe polymer coated member may be functionalized to be hydrophobic so asto provide a bonding between the surface and a mineral particleassociated with one or more hydrophobic molecules.

Furthermore, the polymer can be naturally hydrophobic or functionalizedto be hydrophobic. Some polymers having a long hydrocarbon chain orsilicon-oxygen backbone, for example, tend to be hydrophobic.Hydrophobic polymers include polystyrene, poly(d,l-lactide),poly(dimethylsiloxane), polypropylene, polyacrylic, polyethylene, etc.The mineral particle of interest or the valuable material associatedwith one or more hydrophobic molecules is referred to as a wettedmineral particle. When the pulp slurry contains a plurality ofcollectors or collector molecules, some of the mineral particles willbecome wetted mineral particles if the collectors are attached tomineral particles. Xanthates can be used in the pulp slurry as thecollectors. The functionalized polymer coated member can be coated withhydrophobic silicone polymer including polysiloxanates so that thefunctionalized polymer coated member become hydrophobic. Thefunctionalized polymer coated member can be made of hydrophobicpolymers, such as polystyrene and polypropylene to provide the desiredhydrophobicity.

Combined Collector/Hydrophobic Functionalized Polymer Coated Member

According to some embodiments of the present invention, only a part ofthe surface of the functionalized polymer coated member may beconfigured to have the molecules attached thereto, wherein the moleculescomprise collectors.

According to some embodiments of the present invention, a part of thesurface of the functionalized polymer coated member may be configured tohave the molecules attached thereto, wherein the molecules comprisecollectors, and another part of the surface of the functionalizedpolymer coated member may be configured to be hydrophobic.

According to some embodiments of the present invention, a part of thesurface of the functionalized polymer coated member may be configured tobe hydrophobic.

FIGS. 1, 1 a, 1 b

By way of example, FIG. 1 shows the present invention is the form of amachine, device, system or apparatus 10, e.g., for separating valuablematerial from unwanted material in a mixture 11, such as a pulp slurry,using a first processor 12 and a second processor 14. FIG. 1 includesFIG. 1a and FIG. 1b , where FIG. 1a is a side partial cutaway view indiagram form of a separation processor configured with two chambers,tanks or columns having a functionalized polymer coated impellerarranged therein according to some embodiments of the present invention,and FIG. 1b is a top partial cross-sectional view in diagram form of afunctionalized polymer coated impeller moving in an attachment richenvironment contained in an attachment chamber, tank or column and alsomoving in a release rich environment contained in a release chamber,tank or column. The first processor 12 and the second processor 14 areconfigured with a functionalized polymer coated member that is shown,e.g., as a functionalized polymer coated impeller 20 (FIG. 1a ), 20′(FIG. 1b ), according to some embodiments of the present invention. Inoperation, the impeller 20, 20′ slowly rotates in relation to the firstprocessor 12 and the second processor 14, the impeller blades slowlypass through the attachment rich environment 16 in the first processor12 where the valuable material is attached to the blades and through therelease rich environment 18 in the second processor 14 is released fromthe blades. By way of example, the impeller 20 is shown rotating in acounterclockwise direction as indicated by arrow a, although the scopeof the invention is not intended to be limited to the direction of theimpeller rotation, or the manner in which the functionalized polymercoated impeller 20 (FIG. 1a ), 20′ (FIG. 1b ) is arranged, mounted, orconfigured in relation to the first processor 12 and the secondprocessor 14.

The first processor 12 may take the form of a first chamber, tank, cellor column that contains an attachment rich environment generallyindicated as 16. The first chamber, tank or column 12 may be configuredto receive via piping 13 the mixture or pulp slurry 11 in the form offluid (e.g., water), the valuable material and the unwanted material inthe attachment rich environment 16, e.g., which has a high pH, conduciveto attachment of the valuable material. The second processor 14 may takethe form of a second chamber, tank, cell or column that contains arelease rich environment generally indicated as 18. The second chamber,tank, cell or column 14 may be configured to receive via piping 15,e.g., water 22 in the release rich environment 18, e.g., which may havea low pH or receive ultrasonic waves conducive to release of thevaluable material. Attachment rich environments like that forming partof element environment 16 conducive to the attachment of a valuablematerial of interest and release rich environments like that formingpart of environment 18 conducive to the release of the valuable materialof interest are known in the art, and the scope of the invention is notintended to be limited to any particular type or kind thereof either nowknown or later developed in the future. Moreover, a person skilled inthe art would be able to formulate an attachment rich environment likeenvironment 16 and a corresponding release rich environment likeenvironment 18 based on the separation technology disclosed herein forany particular valuable mineral of interest, e.g., copper, forming partof any particular mixture or slurry pulp.

Although the invention is described as having a high pH in an attachmentenvironment and a low pH in a release environment, embodiments areenvisioned in which the invention will work equally as well where the pHof the attachment environment is selected to optimize the attachment ofdesired materials, such as a low, high or neutral pH, and the pH of therelease environment is selected to be a different pH than the attachmentenvironment and selected to optimize the release of the desiredmaterial.

In operation, the first processor 12 may be configured to receive themixture or pulp slurry 11 of water, valuable material and unwantedmaterial and the functionalized polymer coated member that is configuredto attach to the valuable material in the attachment rich environment16. In FIG. 1, the functionalized polymer coated member is shown as thefunctionalized polymer coated impeller 20 (FIG. 1a ), 20′ (FIG. 1b ). InFIG. 1a , the functionalized polymer coated impeller 20 has a shaft 21and at least one impeller blade 20 a, 20 b, 20 c, 20 d, 2 e, 20 f, 20 gand is configured to rotate slowly inside the first processor 12 and thesecond processor 14. In FIG. 1b , the functionalized polymer coatedimpeller 20′ has a shaft 21′ and impeller blades 20 a′, 20 b′, 20 c′, 20d′, 2 e′, 20 f′, 20 g′ and 20 h′. Each impeller blade in FIG. 1 isunderstood to be configured and functionalized with a polymer coating toattach to the valuable material in the attachment rich environment 16.(The scope of the invention is not intended to be limited to the numberof blades on the impeller 20, 20′ and the embodiment in FIGS. 1a and 1bis shown with impellers 21, 21′ having a different number of blades.)

In FIG. 1, the first processor 12 is configured to receive at least oneimpeller blade of the functionalized polymer coated impeller 20 (FIG. 1a), 20′ (FIG. 1b ). In FIG. 1b , the at least one impeller blade is shownas impeller blade 20 g′ being received in an attachment zone 30 thatforms part of the attachment rich environment 16 defined by walls 30 a,30 b. The first processor 12 may also be configured with a firsttransition zone generally indicated as 40 to provide drainage frompiping 41 of, e.g., tailings 42 as shown in FIG. 1 a.

The first processor 12 may also be configured to provide at least oneenriched impeller blade having the valuable material attached thereto,after passing through the attachment rich environment 16. In FIG. 1b ,the at least one enriched impeller blade is shown as the at least oneenriched impeller blade 20 c′ being provisioned from the attachment richenvironment 16 in the first processor 12 to the release rich environment18 in the second processor 14.

The second processor 14 may be configured to receive via the piping 15the fluid 22 (e.g. water) and the enriched functionalized polymer coatedmember to release the valuable material in the release rich environment18. In FIG. 1b , the second processor 14 is shown receiving the enrichedimpeller blade 20 c′ in a release zone 50, e.g., that forms part of therelease rich environment 18 and is defined, e.g., by walls 30 c and 30d.

The second processor 14 may also be configured to provide the valuablematerial that is released from the enriched functionalized polymercoated member into the release rich environment 18. For example, in FIG.1b the second processor 14 is shown configured with a second transitionzone 60 defined by walls 30 a and 30 d to provide via piping 61 drainageof the valuable material in the form of a concentrate 62 (FIG. 1a ).

FIG. 2: The Functionalized Polymer Coated Conveyor Belt

By way of example, FIG. 2 shows the present invention is the form of amachine, device, system or apparatus 100, e.g., for separating valuablematerial from unwanted material in a mixture 101, such as a pulp slurry,using a first processor 102 and a second processor 104. The firstprocessor 102 and the second processor 104 are configured with afunctionalized polymer coated member that is shown, e.g., as afunctionalized polymer coated conveyor belt 120 that runs between thefirst processor 102 and the second processor 104, according to someembodiments of the present invention. The arrows A1, A2, A3 indicate themovement of the functionalized polymer coated conveyor belt 120.Techniques, including motors, gearing, etc., for running a conveyor beltlike element 120 between two processors, such as elements 102 and 104are known in the art, and the scope of the invention is not intended tobe limited to any particular type or kind thereof either now known orlater developed in the future. According to some embodiments of thepresent invention, the functionalized polymer coated conveyor belt 120may be made of a mesh material.

The first processor 102 may take the form of a first chamber, tank, cellor column that contains an attachment rich environment generallyindicated as 106. The first chamber, tank or column 102 may beconfigured to receive the mixture or pulp slurry 101 in the form offluid (e.g., water), the valuable material and the unwanted material inthe attachment rich environment 106, e.g., which has a high pH,conducive to attachment of the valuable material. The second processor104 may take the form of a second chamber, tank, cell or column thatcontains a release rich environment generally indicated as 108. Thesecond chamber, tank, cell or column 104 may be configured to receive,e.g., water 122 in the release rich environment 108, e.g., which mayhave a low pH or receive ultrasonic waves conducive to release of thevaluable material. Consistent with that stated above, attachment richenvironments like that forming part of element environment 106 conduciveto the attachment of a valuable material of interest and release richenvironments like that forming part of environment 108 conducive to therelease of the valuable material of interest are known in the art, andthe scope of the invention is not intended to be limited to anyparticular type or kind thereof either now known or later developed inthe future. Moreover, a person skilled in the art would be able toformulate an attachment rich environment like environment 106 and acorresponding release rich environment like environment 108 based on theseparation technology disclosed herein for any particular valuablemineral of interest, e.g., copper, forming part of any particularmixture or slurry pulp.

In operation, the first processor 102 may be configured to receive themixture or pulp slurry 101 of water, valuable material and unwantedmaterial and the functionalized polymer coated conveyor belt 120 that isconfigured to attach to the valuable material in the attachment richenvironment 106. In FIG. 2, the belt 120 is understood to be configuredand functionalized with a polymer coating to attach to the valuablematerial in the attachment rich environment 106.

The first processor 102 may also be configured to provide drainage frompiping 141 of, e.g., tailings 142 as shown in FIG. 2.

The first processor 102 may also be configured to provide an enrichedfunctionalized polymer coated conveyor belt having the valuable materialattached thereto, after passing through the attachment rich environment106. In FIG. 2, the enriched functionalized polymer coated conveyor beltis shown, e.g., as that portion or part 120 a of the belt 120 beingprovisioned from the attachment rich environment 106 in the firstprocessor 102 to the release rich environment 108 in the secondprocessor 104. It is understood that some other portions or parts of thebelt 120 may be enriched, including the portion or part immediatelyleaving the attachment rich environment 106, as well as the portion orpart immediately entering the release rich environment 108.

The second processor 14 may be configured to receive the fluid 122 (e.g.water) and the portion 120 a of the enriched functionalized polymercoated conveyor belt 120 to release the valuable material in the releaserich environment 108.

The second processor 104 may also be configured to provide the valuablematerial that is released from the enriched functionalized polymercoated member into the release rich environment 108. For example, inFIG. 2 the second processor 104 is shown configured to provide viapiping 161 drainage of the valuable material in the form of aconcentrate 162.

In FIG. 2, the first processor 102 is configured with the functionalizedpolymer coated conveyor belt 120 passing through with only two turnsinside the attachment rich environment 106. However, embodiments areenvisioned in which the first processor 102 may be configured to processthe functionalized polymer coated conveyor belt 120 using a serpentinetechnique for winding or turning the belt 120 one way and another way,back and forth, inside the first processor to maximize surface area ofthe belt inside the processor 102 and exposure of the belt 120 to theattachment rich environment 106.

FIG. 3: The Functionalized Polymer Coated Filter

By way of example, FIG. 3 shows the present invention is the form of amachine, device, system or apparatus 200, e.g., for separating valuablematerial from unwanted material in a mixture 201, such as a pulp slurry,using a first processor 202, 202′ and a second processor 204, 204′. Thefirst processor 202 and the second processor 204 are configured toprocess a functionalized polymer coated member that is shown, e.g., as afunctionalized polymer coated collection filter 220 configured to bemoved between the first processor 202 and the second processor 204′ asshown in FIG. 3 as part of a batch type process, according to someembodiments of the present invention. In FIG. 3, by way of example thebatch type process is shown as having two first processors 202, 202′ andsecond processors 204, 204, although the scope of the invention is notintended to be limited to the number of first or second processors.Moreover, embodiments are envisioned using a different number of firstand second processors, different types or kinds of processors, as wellas different types or kinds of processors both now known or laterdeveloped in the future. According to some embodiments of the presentinvention, the functionalized polymer coated collection filter 220 maytake the form of a membrane or a thin soft pliable sheet or layer. Thearrow B1 indicates the movement of the functionalized polymer coatedfilter 220 from the first processor 202, and the arrow B2 indicates themovement of the functionalized polymer coated collection filter 220 intothe second processor 202. Techniques, including motors, gearing, etc.,for moving a filter like element 220 from one processor to anotherprocessor like elements 202 and 204 are known in the art, and the scopeof the invention is not intended to be limited to any particular type orkind thereof either now known or later developed in the future.

The first processor 202 may take the form of a first chamber, tank, cellor column that contains an attachment rich environment generallyindicated as 206. The first chamber, tank or column 102 may beconfigured to receive the mixture or pulp slurry 201 in the form offluid (e.g., water), the valuable material and the unwanted material inthe attachment rich environment 206, e.g., which has a high pH,conducive to attachment of the valuable material. The second processor204 may take the form of a second chamber, tank, cell or column thatcontains a release rich environment generally indicated as 208. Thesecond chamber, tank, cell or column 204 may be configured to receive,e.g., water 222 in the release rich environment 208, e.g., which mayhave a low pH or receive ultrasonic waves conducive to release of thevaluable material. Consistent with that stated above, attachment richenvironments like that forming part of element environment 206 conduciveto the attachment of a valuable material of interest and release richenvironments like that forming part of environment 208 conducive to therelease of the valuable material of interest are known in the art, andthe scope of the invention is not intended to be limited to anyparticular type or kind thereof either now known or later developed inthe future. Moreover, a person skilled in the art would be able toformulate an attachment rich environment like environment 206 and acorresponding release rich environment like environment 208 based on theseparation technology disclosed herein for any particular valuablemineral of interest, e.g., copper, forming part of any particularmixture or slurry pulp.

In operation, the first processor 202 may be configured to receive themixture or pulp slurry 101 of water, valuable material and unwantedmaterial and the functionalized polymer coated collection filter 220that is configured to attach to the valuable material in the attachmentrich environment 206. In FIG. 3, the functionalized polymer coatedcollection filter 220 is understood to be configured and functionalizedwith a polymer coating to attach to the valuable material in theattachment rich environment 106.

The first processor 202 may also be configured to provide drainage frompiping 241 of, e.g., tailings 242 as shown in FIG. 3.

The first processor 202 may also be configured to provide an enrichedfunctionalized polymer coated collection filter having the valuablematerial attached thereto, after soaking in the attachment richenvironment 106. In FIG. 3, the enriched functionalized polymer coatedcollection filter 220 is shown, e.g., being provisioned from theattachment rich environment 206 in the first processor 202 to therelease rich environment 208 in the second processor 204.

The second processor 204 may be configured to receive the fluid 222(e.g. water) and the enriched functionalized polymer coated collectionfilter 220 to release the valuable material in the release richenvironment 208.

The second processor 204 may also be configured to provide the valuablematerial that is released from the enriched functionalized polymercoated collection filter 220 into the release rich environment 208. Forexample, in FIG. 3 the second processor 204 is shown configured toprovide via piping 261 drainage of the valuable material in the form ofa concentrate 262.

The first processor 202′ may also be configured with piping 280 andpumping 280 to recirculate the tailings 242 back into the firstprocessor 202′. The scope of the invention is also intended to includethe second processor 204′ being configured with corresponding piping andpumping to recirculate the concentrate 262 back into the secondprocessor 204′. Similar recirculation techniques may be implemented forthe embodiments disclosed in relation to FIGS. 1-2 above.

The scope of the invention is not intended to be limited to the type orkind of batch process being implemented. For example, embodiments areenvisioned in which the batch process may include the first and secondprocessors 202, 204 being configured to process the enrichedfunctionalized polymer coated collection filter 220 in relation to onetype or kind of valuable material, and the first and second processors202′, 204′ being configured to process the enriched functionalizedpolymer coated collection filter 220 in relation to either the same typeor kind of valuable material, or a different type or kind of valuablematerial. Moreover, the scope of the invention is intended to includebatch processes both now known and later developed in the future.

It should be noted that the functionalized polymer coated member of thepresent invention can be realized by a different way to achieve the samegoal. Namely, it is possible to use a different means to attract themineral particles of interest to the surface of the functionalizedpolymer coated member. For example, the surface of the polymer coatedmember can be functionalized with a hydrophobic chemical molecule orcompound, as discussed below. Alternatively, the surface of thefunctionalized polymer coated member can be coated with hydrophobicchemical molecules or compounds. In the pulp slurry, xanthate andhydroxamate collectors can also be added therein for collecting themineral particles and making the mineral particles hydrophobic. When thefunctionalized polymer coated member is used to collect the mineralparticles in the pulp slurry having a pH value around 8-9, it ispossible to release the mineral particles on the enriched syntheticbeads from the surface of the functionalized polymer coated member in anacidic solution, such as a sulfuric acid solution. According to someembodiment, it may also be possible to release the mineral particlescarried with the enriched functionalized polymer coated member by sonicagitation, such as ultrasonic waves, or simply by washing it with water.

FIGS. 4 a-4 f

According to some embodiments of the present invention, the foam orsponge can take the form of a filter, a membrane or a conveyor belt asdescribed in PCT application no. PCT/US12/39534 (Atty docket no.712-002.359-1), entitled “Mineral separation using functionalizedmembranes;” filed 21 May 2012, which is hereby incorporated by referencein its entirety. A a porous material, foam or sponge may be generalizedas a material with three-dimensional open-cellular structure, anopen-cell foam or reticulated foam, which can be made from soft polymersand may include a hydrophobic chemical having molecules to attract andattach mineral particles to the surfaces of the polymer-coatedsubstrate.

Open-cell foam or reticulated foam offers an advantage over non-opencell materials by having higher surface area to volume ratio. Applying afunctionalized polymer coating that promotes attachment of mineral tothe foam “network” enables higher mineral recovery rates and alsoimproves recovery of less liberated mineral than conventional process.For example, the open cells in an engineered foam block allow passage offluid and particles smaller than the cell size but captures mineralparticles that come in contact with the functionalized polymer coatingon the open cells. This also allows the selection of cell size dependentupon slurry properties and application.

According to some embodiments of the present invention, the substratetakes the form of an open-cell foam/structure in a rectangular block ora cubic shape 70 a as shown in FIG. 4 a.

According to some embodiments of the present invention, the substratemay take the form of a filter 70 b with a three-dimensional open-cellstructure as shown in FIG. 4b . The filter 70 b can be used in afiltering assembly 220 as shown in FIG. 5, for example.

According some embodiments of the present invention, the substrate maytake the form of a membrane 70 c, a section of which is shown in FIG. 4c. As seen in FIG. 4c , the membrane 70 c can have an open-cell foamlayer or filter 70 b attached to a base or backing member 73. Thebacking member can be made from a material which is less porous than theopen-cell foam layer. For example, the backing member can be a sheet ofpliable polymer to enhance the durability of the membrane. The membrane70 c can be used as a conveyor belt as shown in FIG. 2, for example.

According some embodiments of the present invention, the substrate maytake the form of a membrane 70 d, a section of which is shown in FIG. 4d. As seen in FIG. 4d , the membrane 70 d can have two open-cell foamlayers or filters 70 b attached to two sides of a backing member 73. Thebacking member 73 can made of a material which is less porous than theopen-cell foam layer. The membrane 70 d can also be used as a conveyorbelt as shown in FIG. 2, for example.

An example of the polymer-coated member is shown in FIG. 4e . As shownin FIG. 4e , the polymer-coated member 79 comprises an open-cell foamlayer 70 b and two polymeric coatings 77. Another example of thepolymer-coated member is shown in FIG. 4f . As shown in FIG. 4f , thepolymer-coated member 79 comprises a membrane 70 d and two polymericcoatings 77.

FIGS. 5-7

The mineral particle or the valuable material associated with one ormore amphiphilic collector molecules is referred to as a wetted mineralparticle. When the pulp slurry contains a plurality of collectors orcollector molecules, some of the mineral particles will become wettedmineral particles if the collectors are attached to mineral particles,thus making the surface of the mineral particles hydrophobic. Xanthatescan be used in the pulp slurry as the collectors.

In effect, the key mechanism for the materials is the combination ofhydrophobicity, tackiness and compliance. By way of example, accordingto some embodiments of the present invention, the mechanism works asfollows:

1. The hydrophobicity of the surface provides the selectivity. When inthe water based solution, the hydrophobic surface attracts thehydrophobic minerals of interest, and rejects the non-hydrophobic ganguematerials.

2. As the hydrophobic material is removed from the solution, thetackiness of the material maintains the contact and “grip” on thecollected hydrophobic minerals (which would otherwise fall off becausethere is no hydrophobic action to hold them in place after withdrawalfrom the solution).

3. Compliance is also a key component. Material compliance is essentialto allow surface area contact in hydrophobic conditions, and further toallows surface area contact under tacky conditions after withdrawal fromthe solution. This may also be due at least in part to Van der Waalsforces.

4. Another important feature is durability, with the understanding thatthere may be a tradeoff between durability and compliance and/ortackiness. One typically may want durability if one intends to reuse thematerials (to make the process cost effective), but if one make thematerial too durable, one may lose either the compliance and/ortackiness feature of the material, thus the trade-off.

It should be understood that, when the collection area of the impeller20 (FIGS. 1a, 1b ), the collection area of the conveyor belt 120 (FIG.2) and the collection area 223 of the filter 220 (FIG. 6) arefunctionalized to be hydrophobic, the pulp slurry 11 (FIG. 1a ), thepulp slurry 101 (FIG. 2) and the pulp slurry 201 (FIG. 3) may be mixedwith collector molecules such as xanthates so that the mineral particlesin the slurry may be hydrophobically modified with the collectormolecules to become wetted mineral particles.

In a different embodiment of the present invention, the impeller 20(FIG. 1a ), the conveyor belt 120 (FIG. 2) and the filter 220 (FIG. 3)are used in a horizontal pipeline for mineral separation. Furthermore, agroup of filters 220 can be used in a first processor 202 as shown inFIG. 3. By way of example, a plurality of filters 220 are placed into ahorizontal pipeline 300 to collect the valuable material in the slurry322, as shown in FIG. 5. As the slurry passes through the filters 220,some of the mineral particles in the slurry will become attached tocollection area 223 and the openings. With such an arrangement, one ormore of the filters 220 can be taken out of the horizontal pipeline 300for mineral releasing (see FIG. 6) while other filters 220 continue tocollect the mineral particles. The tailings 342 can be discharged ortransported to a tailings pond or the like (see FIG. 7). The attachedmineral particles on the filter 220 can be released in a release richenvironment with a low pH solution and/or ultrasonic agitation. The pHvalue of the low pH solution can be 0 to 7, for example. As shown inFIG. 6, the filter 220 with collected mineral particles can be placed ina releasing apparatus 410 to be washed with a mixture of acid and waterprovided by water container 424 and acid container 422. One or moreultrasonic sources 432 may be used to shake loose the attached mineralparticles from the filter 220.

FIGS. 8-15

The present invention provides a number of coating systems for applyinga polymeric coating onto one or both sides of a substrate to achieve apolymer-coated member (see FIGS. 4e and 4f , for example). Thepolymeric-coating provides a compliant, tacky surface of low energy inorder to enhance selective collection of hydrophobic and hydrophobizedmineral particles ranged widely in particle size when distributed in anaqueous slurry. In one embodiment of the present invention, thepolymeric-coating is functionalized to become hydrophobic.

To demonstrate how the substrate is coated with the polymeric coatingmaterial, an open-cell foam filter 70, such as the filter 70 b as shownin FIG. 4b is used as the substrate.

FIG. 8 illustrates a two-roll flooded-nip coater 501, according to anembodiment of the present invention. The two-roll flooded-nip coater 501can be used to apply one side or both sides of the foam filter 70. Asshown in FIG. 8, two rollers 511 are placed side-by-side horizontallywith a gap between them. The roller speed and size is independentlycontrolled and may be different for each roller, according to anembodiment of the present invention. Furthermore, the roller temperaturemay be individually controlled. The coating material 177 is placed inexcess into the roller gap and the filter 70 is fed into the gap andthrough the roller system. The gap distance between the rollers 511 issignificantly smaller than the foam thickness. The gap distance may besmaller than half of the thickness so as to impregnate the open-cellstructure of the reticulated foam with the coating material. Accordingto an embodiment of the present invention, the gap distance may be assmall as 2% of the foam thickness. After the foam filer 70 passedthrough the roller system, each side of the foam filer 70 has apolymeric coating 77 and the polymer-coated foam filter 70 is shown as apolymer-coated member 79.

FIG. 9 illustrates a roll coater 502 with a spray manifold, according toan embodiment of the present invention. As shown in FIG. 9, two sprayers160 are placed on the sides of the foam filter 70 to spray coatingmaterial 177 on the filter surfaces. The coating material 177 is sprayedonto each side of the foam filter 70 in an amount equal to the desiredcoating weight or higher. The coated foam filter is fed between tworollers 511 in order to distribute the coating homogeneously throughoutthe foam structure. High viscosity coating material can be diluted toreduce viscosity and make it sprayable. Temperature can be increased toreduce viscosity. Dilution and temperature-increase should be balancewith the pot life of curable coating. After the foam filer 70 passedthrough the roller system, each side of the foam filer 70 has apolymeric coating 77 and the polymer-coated foam filter 70 is shown as apolymer-coated member 79.

FIG. 10 illustrates a roll-coater 503 with an extruder system, accordingto an embodiment of the present invention. As shown in FIG. 10, anextruder 150 is used to extrude the coating material 177 on each side ofthe foam filter 70. The coated foam filter is fed between two rollers511 in order to distribute the coating homogeneously throughout the foamstructure. After the foam filer 70 passed through the roller system,each side of the foam filer 70 has a polymeric coating 77 and thepolymer-coated foam filter 70 is shown as a polymer-coated member 79.

FIG. 11 illustrates a roll coater 504 with porous roller 513, accordingto an embodiment of the present invention. As shown in FIG. 11, twoporous rollers 513 are placed side-by-side horizontally with a gapbetween them. Each of the porous rollers 513 may be arranged to contacta material supply source so that the coating material 177 is fed throughthe porous rollers 513 that compress and apply the coating material 177onto the foam filter 70. After the foam filer 70 passed through theroller system, each side of the foam filer 70 has a polymeric coating 77and the polymer-coated foam filter 70 is shown as a polymer-coatedmember 79. The porous rollers 513 may be made of metal, ceramic oropen-cell foam.

FIG. 12 illustrates an immersion coater 505, according to an embodimentof the present invention. As shown in FIG. 12, the foam filter 70 is fedthrough a bulk coating vessel such as a container 178 containing thecoating material 177. The foam filter 70 with coating material 177 isfed through the rollers 511 to remove the excess coating material. Afterthe foam filer 70 passed through the roller system, each side of thefoam filer 70 has a polymeric coating 77 and the polymer-coated foamfilter 70 is shown as a polymer-coated member 79.

FIG. 13 illustrates a coating system 506 using vacuum impregnation,according to an embodiment of the present invention. As shown in FIG.13, the foam filter 70 is placed in a bulk coating vessel such as avacuum chamber 277 containing coating material 177. The vacuum insidethe chamber 277 draws the coating material 177 into the foam filter 70.The coated foam filter is fed between two rollers 511 in order todistribute the coating homogeneously throughout the foam structure.After the foam filer 70 passed through the roller system, each side ofthe foam filer 70 has a polymeric coating 77 and the polymer-coated foamfilter 70 is shown as a polymer-coated member 79.

FIG. 14 illustrates a metering-roll coater 507, according to anembodiment of the present invention. Various roll configurations may beused to apply the coating material 177 onto the foam filter 70. As shownin FIG. 14, each pick-up roll 512 may be immersed in the coatingmaterial 177 in a container 178. The coating material 177 is then offsetonto the coating roll 511 and then onto the foam filter 70. The coatingmaterial 177 on the coating roll 511 may be optimized by offsetting ontoa metering roll, doctor roll or doctor blade. According to an embodimentof the present invention, a series of rolls can carry the coatingmaterial from a reservoir to a pick-up roller, transfer roll, thecoating roll and onto the foam filter 70. Excess coating material can beremoved by running the coated foam filter through a back-up roll and aMayer bar or Wiper bar with the excess coating material returned to thereservoir, for example.

Applications

The scope of the invention is described in relation to mineralseparation, including the separation of copper from ore.

By way of example, applications are envisioned to include

Rougher, scavenger, cleaner and rougher/scavenger separation cells inthe production stream, replacing the traditional flotation machines.

Tailings scavenger cells used to scavenge the unrecovered minerals froma tailings stream.

Tailings cleaning cell used to clean unwanted material from the tailingsstream before it is sent to the disposal pond.

Tailings reclamation machine that is placed in the tailings pond torecover valuable mineral that has been sent to the tailings pond.

Other types or kinds of valuable material or minerals of interest,including gold, molybdenum, etc.

However, the scope of the invention is intended to include other typesor kinds of applications either now known or later developed in thefuture, including applications related to oilsands separation thatincludes separating bitumen from sand and water in the recovery ofbitumen in an oilsands mining operation.

THE SCOPE OF THE INVENTION

It should be further appreciated that any of the features,characteristics, alternatives or modifications described regarding aparticular embodiment herein may also be applied, used, or incorporatedwith any other embodiment described herein. Although the invention hasbeen described and illustrated with respect to exemplary embodimentsthereof, the foregoing and various other additions and omissions may bemade therein and thereto without departing from the scope of the presentinvention.

What is claimed is:
 1. A process for coating a substrate comprising areticulated foam, comprising: arranging a first roller and a secondroller adjacent to each other substantially in a horizontal direction,the second roller and the first roller separated by a gap, the gaphaving an upper portion and a lower portion; positioning the substrateon the upper portion of the gap, the substrate having a substratethickness greater than the gap; providing a coating material onto thesubstrate, and feeding the substrate from the upper portion of the gapthrough the lower portion of the gap so as to achieve a layer of thecoating material on the substrate.
 2. The process according to claim 1,wherein the substrate has two surfaces arranged to contact both thefirst roller and the second roller simultaneously through the gap. 3.The process according to claim 2, wherein the coating material isprovided on the upper portion of the gap and the two surfaces of thesubstrate are caused to pick up the coating material while the substrateis moved through the upper portion of the gap toward the lower portionof the gap.
 4. The process according to claim 2, wherein the coatingmaterial is sprayed onto the two surfaces of the substrate above thegap.
 5. The process according to claim 2, wherein the coating materialis extruded onto one or both surfaces of the substrate above gap.
 6. Theprocess according to claim 2, wherein the first roller and the secondroller are porous rollers and wherein the coating material is arrangedto load onto the porous rollers so as to cause the coating material onthe porous rollers to transfer onto the substrate as part of eachrollers is compressed when the substrate is fed from the upper portionthrough the lower portion of the gap.
 7. The process according to claim2, wherein the coating material is contained in a vessel, and thesubstrate is arranged to move through the vessel to pick up the coatingmaterial before the substrate is fed from the upper portion through thelower portion of the gap.
 8. The process according to claim 2, whereinthe coating material is contained in a vacuum chamber and the substrateis arranged to locate in the vacuum chamber in order to draw the coatingmaterial onto the substrate before the substrate is fed from the upperportion through the lower portion of the gap.
 9. The process accordingto claim 2, further comprising: one or more rolls arranged to pick upthe coating material and to transfer the picked up coating material ontothe first roller and the second roller, and wherein the first and secondrollers arranged to provide the transferred coating material onto thesubstrate before the substrate is fed from the upper portion through thelower portion of the gap.
 10. The process according to claim 1, whereinthe coating material is selected from the group consisting of apolysiloxane derivative, acrylic polymer, butyl rubber, ethylene vinylacetate, natural rubber, nitriles, styrene block copolymers withethylene, styrene block copolymers with propylene, styrene blockcopolymers with isoprene, polyurethane and polyvinyl ether.
 11. Theprocess according to claim 1, wherein the reticulated foam comprises aplurality of pores having a pore size ranging from 5 PPI to 120PPI. 12.The process according to claim 1, wherein the reticulated foam has afoam thickness ranged from 1/32″ to 6″.
 13. The process according toclaim 1, further comprising a heater and/or a blower arranged toaccelerate curing of the layer of the coating material on the substrate.14. The process according to claim 1, wherein the gap has a gap distancewhich is 0.02 of the substrate thickness.
 15. The process according toclaim 1, wherein the layer is further functionalized to be hydrophobicso as to attract mineral particles in a slurry.
 16. A polymer-coatedmember configured to contact a slurry containing mineral particles, thepolymer-coated member comprising: a substrate comprising a reticulatedfoam having open-cell foam structure, the substrate having two surfaces,the reticulated foam having a foam thickness; a polymeric coatingdisposed on one or both of the two surfaces, the polymeric-coating madefrom a coating material comprising a polymer to render the polymericcoating compliant and tacky, wherein the substrate is arranged to movethrough a pair of rollers arranged adjacent to each other substantiallyin a horizontal direction, the rollers separated from each other by agap having an upper portion and a lower portion, wherein the coatingmaterial is arranged to provide onto the substrate above the gap and thegap is dimensioned to compress the reticulated foam so as to impregnatethe open-cell foam structure with the coating material when thesubstrate is moved from the upper portion of the gap through the lowerportion of the gap to achieve the polymeric coating.
 17. Thepolymer-coated member according to claim 16, wherein the polymer coatingcomprises a chemical having a functional group rendering said one or twosurfaces hydrophobic so as to attract the miner particles.
 18. Thepolymer-coated member according to claim 16, wherein the coatingmaterial is selected from the group consisting of a polysiloxanederivative, acrylic polymer, butyl rubber, ethylene vinyl acetate,natural rubber, nitriles, styrene block copolymers with ethylene,styrene block copolymers with propylene, styrene block copolymers withisoprene, polyurethane and polyvinyl ether.
 19. The polymer-coatedmember according to claim 16, wherein the polymeric coating is modifiedwith a material selected from the group consisting of tackifiers;plasticizers; crosslinking agents; chain transfer agents; chainextenders; adhesion promoters; aryl or alky copolymers; fluorinatedcopolymers and/or additives; hydrophobizing agents such ashexamethyldisilazane; inorganic particles such as silica, hydrophobicsilica, and/or fumed hydrophobic silica; MQ resin; and/or otheradditives to control and modify the properties of the polymer.
 20. Thepolymer-coated member according to claim 16, wherein the polymericcoating is further modified with a chemical selected from the groupconsisting of alkyl, aryl, fluorinated functionalities; silica-basedadditives and other inorganics such as clays and/or bentonite; lowmolecular weight and oligomeric plasticizers and POSS materials.